Process of treating gold and silver ores.



/" No. '776.424, PATENTED Nov. 29, 1904.

C. H. RIDER.

PROCESS OF TREATING GOLD AND SILVER GRES. l

APPLICATION FILED MAR. 19, 1903` N0 MODEL.

' UNITED STATES Patented November 29, 1904,

- PATENT OFFICE.

CHARLES H. RIDER, OF ST. LOUIS, MISSOURI.

SPECIFICATION forming part of Letters Patent No. 776,424, dated November29, 1904.

Original application filed May 22, 1902, Serial No. 108,519. Divided andthis application filed March 19, 1903. Serial No. 148,570. (Nospecimens.)

To all whom, t may concern:

Be it known that I, CHARLES H. RIDER, a citizen of the United States,residing at St. Louis, Missouri, have invented a certain new and usefulImprovement in Processes of Treating' Gold and Silver Orcs, of which thefollowing is a full, clear, and exact description, such as Will enableothers skilled in the art to which it appertains to make and use thesame, reference being had to the accompanying drawings, forming part ofthis specification.

This application is a division from an application filed by me May 22,1902, Serial N o. 108,519, for process of treating ores.

This invention relates to a new and useful process of extracting metalfrom ores, the object being to extract metals, such as gold in Inetallicstate, while silver is precipitated as chlorid.

Another object of my improved process is to recover the extracting andprecipitating agents in the form of byproducts for repeated use incarrying on my process.

In the drawings I have shown an apparatu for working my improvedprocess, the same in this instance consisting of eight tanks numbered,respectively, from l to 8, inclusive, said tanks being connected bypipes running from the top of one of them down into the bottom of thenext adjacent tank of higher order. These tanks are constructed ofwoodand made so as to be preferably air-tight by the use of rubber placedunder a removable cover arranged in the top wall thereof and adumping-door being' arranged in the bottom thereof. Openings are alsoprovided whereby the resultant liquid in the tanks may be racked ordrawn oii'. In general operation the ore after being finely pulverizedis placed in tanks 1 to 4, inclusive, and the dissolving' solution addedthrough the opening in the top, said opening being subsequently closed.The action of the chemicals on the pulverized ore causes a steady andrapid iiow of gas from the top of one tank to the bottom of the nextadjacent tank of higher order, which results in keeping the oreconstantly in motion until all the soluble matter is decomposed, whichis effected usually in from ten to twelve hours. This agitation of theore effects a quicker decomposition than would be possible if the orewas permitted to lie'in a quiescent state in the bottoms of the severaltanks. After the decomposition referred to suflcient time is allowed forthe solid matter to settle, and the clear fluid is drawn off and placedin tanks 5 to 8, with a sufficient quantity of a saturated solution ofsodium chlorid. The residue in tanks 1 to 4 is preferably washed withclear Water and allowed to settle, after which the water is transferredto the clear iiuid. The residue in tanks 1 to 4 in the form of sulfur,silica, or earthy matter is discharged through the openings in thebottoms of the respective tanks. For the sake of description I will termtanks 5 to 8 the "precipitating-tanks, into which the clear solutionfrom tanks 1 to 4 is placed in following' the first step of my process.'The second step consists in recharging the first four tanks andrepeating the operation above described, the resultant gases producedthereby being carried through the precipitating-tanks for the purpose ofagitating the iiuid after the proper precipitating reagent has beenadded thereto. This agitation of the contents in the precipitating-tankshastens this operation, and in most cases the gases coming over from thedecomposing-tanks supply some necessary element or elements required.

In practicing' my improved process in connection with gold and silverores I proceed as follows: The ore is ground or crushed to size whichwill pass through a twenty to forty mesh sieve. A charge ofapproximately live hundred pounds is added to each of the tanks 1 to 4.To this is added in each tank a solution which is made up of water, onehundred gallons; commercial sulfuric acid, three to five gallons, andcommercial nitric acid, fifteen to twenty gallons. After the silver isdissolved from the ore remove the solution to the tanks 5 to 8 and add afresh solution to the undissolved ore, composed of water, forty gallons;nitric acid, five gallons, and hydrochloric acid, ten gallons. This willdissolve the gold, and by adding this solution to the solution now inthe tanks 5 to 8 will cause an immediate precipitation of the silver aschlorid. Remove the solution from which the silver has been precipitatedand precipitate the gold by adding one or two quarts of a saturatedsolution of ferrous sulfate. This brings the gold down in a metallicstate. In

v extracting' gold and silver it is best to have ten o1' more tanks,using one or two tanks following the ore-tanks, said last-mentionedtanks being partly filled with water. This will take up the gases fromthe ore-tanks, forming an acid, usually nitric and hydrochloric, to beusedagain in the next charge, in which case less acid may be used thanabove stated.

Having thus described my invention, what Iclaim as new, and desire tosecure by Letters Patent, is-

l. The herein-described process of treating gold and silver bearingores, which consists in placing a charge of approximately live hundredpounds of crushed ore in each of the four receptacles, adding in eachreceptacle a solution composed of one hundred gallons of water, three tofive gallons of commercial sulfuric acid, and fifteen to vtwenty gallonsof commercial nitric acid, and after the silver is dissolved removingthe resultant solution to new receptacles, adding the fresh solution tothe undissolved ore in the first receptacle, said solution comprisingforty gallons of water, five gallons of nitric acid, and ten gallons ofhydrochloric acid, thus dissolving the gold in the iirst receptacle,then combining the two solutions and precipitating the silver,substantially as described.

2. The herein-described process of treating gold and silver bearingores, which consists of placing a charge of crushed ore in a receptacle,adding in the receptacle a solution composed of water, sulfuric acid andnitric acid, to dissolve the silver, removing the silver-bearingsolution to a new receptacle, adding a fresh solution to the undissolvedore in the first receptacle, said fresh solution comprising water,nitric acid, and hydrochloric acid, to dissolve the gold, then combiningthe gold and silver bearing solutions and precipitating -the silver;substantially as specified.

3. The herein-described process of treating gold and silver bearingores, which consists of placing a charge of crushed ore in a receptacle,adding in the receptacle a solution composed of water, sulfuric acid andnitric acid, to dissolve the silver, removing the silver-bearingsolution to a new receptacle, adding a fresh solution to the undissolvedore in the first receptacle, said fresh solution comprising water,nitric acid and hydrochloric acid, to dissolve the gold, then combiningthe gold and silver bearing solutions and precipitating the silver,removing the solution from the silver and adding ferrous sulfate toprecipitate the gold; substantially as specified.

In testimony whereof I hereunto aiiiX my signature, in the presence oftwo witnesses, this 2d day of March, 1903.

CHARLES H. RlDER.

Witnesses:

F. H. GIBBs, GEORGE BAKEWELL.

